Ash Barty won the match 6-3, 7-6 (7-2) to end a 44-year wait for an Australian to win their home Grand Slam.
Under the lights on Rod Laver Arena, the second seed showed a mix of quality and grit in defeating fourth seed Stefanos Tsitsipas 7-6(5), 4-6, 6-4, 6-1.
Playing under the roof on Rod Laver Arena, Nadal was in complete control for two sets and recovered from losing the third.
Swiatek, who was defeated by the American 6-4 6-1 in 78 minutes, also advanced to the semi-finals of the tune-up event in Adelaide.
Ashleigh Barty defeated Madison Keys while Danielle Collins saw off seventh seed Iga Swiatek for a meeting in the final.
A resurgent Danielle Collins has joined her compatriot Madison Keys in the Australian Open semifinals.
Denis Shapovalov lost to Rafael Nadal in five sets in the quarterfinal of the Australian Open 2022.
Kaia Kanepi completed her career set of Grand Slam quarter-finals with a stunning come-from-behind win over second seeded Aryna Sabalenka at the 2022 Australian Open.
Daniil Medvedev, Jannik Sinner and Felix Auger-Aliassime are all through to the quarterfinals of the Australian Open 2022.
Sania Mirza remains the only Indian in fray at the Australian Open 2022 contesting in the mixed doubles with her American partner Rajeev Ram.